1) I am having confusion in using articles, could you give a brief idea about it, particularly in the usage of 'the'
"the" is used to address a particular noun, like when I say "Let's go to the park", I am referring to a specific park. When I say
"Let's go to a park", I am not specifying a particular park, any park will do.
2) which is right? childrens' or children's
'children' is the plural for 'child' so only the word children's exist
3) when should we use comma.
a) it is famous across the world, especially among young. Should i use comma before especially?
b) It is crucial for them, importantly, for children. should i use two comma here?
c) it has many features, namely, video, photos and recording. should i use two commas here?
usage of comma really depends on the writer, think of it this way: 'comma' is a small stop while 'period' is a full stop for your reader
so it is upon the writer's discretion on how he wants the reader to read his essay
naturally you would want to put commas on most cohesive words and items you enumerate
4)a)if they ask for do you agree or disagree in ielts exam, do we need to write the cons of that subject or so do we need to focus only on pros?
in my opinion and experience, if I strongly agree on one side, then I won't talk about the opposing side
if I partly agree and disagree on the theory, then I should write about both sides
6)which is correct? lifestyle or life-style. can we use pleural form for lifestlye?
try to stick with lifestyle and its plural lifestyles
hope this helps...